Expander system for stepwise expansion of a tubular element

摘要

An expander system for radially expanding a tubular element having an unexpanded portion of a first inner diameter, the expander system including an expander movable between a radially retracted mode and a radially expanded mode, the expander being operable to expand the tubular element from the first inner diameter to a second inner diameter larger than the first inner diameter by movement of the expander from the radially retracted mode to the radially expanded mode thereof, wherein the expander has a contact section of a diameter larger than the first inner diameter when the expander is in the radially retracted mode, and wherein the contact section is arranged to prevent axial movement of the expander through the unexpanded portion of the tubular element when the expander is in the radially retracted mode.